31 巻 (2015) 2 号 p. 128-134
We tested the reputation maintenance hypothesis of ingroup favoritism. Ninety-two non-student participants played one-shot prisoner’s dilemma games with an ingroup and an outgroup partner with minimal groups, and showed ingroup favoritism only when the participant and his/her partner knew each other’s group membership (common knowledge condition). The ingroup favoritism observed in the common knowledge condition positively correlated with fear of negative evaluation. These results provide support for the reputation maintenance hypothesis.